3366 - update requirements with buster versions

requirements.txt

 git+https://gitlab.com/xivo.solutions/xivo-lib-python.git
 git+https://gitlab.com/xivo.solutions/xivo-provd-client.git
-psycopg2-binary==2.7.5
-pyyaml==3.12
-sqlalchemy==1.0.15
+psycopg2-binary==2.8.4
+pyyaml==3.13
+sqlalchemy==1.2.18